1. Voluntary written informed consent of the participant or their legally authorized representative has been obtained prior to any screening procedures
2. Male or female patients of at least 18 years old.
3. Availability of the results of a basic work-up:
1. Medical history, demographic information and clinical information (including BMI)
2. Laboratory tests including hemoglobin, hematocrit and uric acid
3. ECG
4. Pulmonary function tests
5. Echocardiography
4. Intermediate to high probability of PH based on echocardiography according to the 2022 ESC/ERS guidelines (see Figure 2 and Table 2). (1)
5. Indication for RHC according to ESC/ERS 2022 guidelines. (1)
You may not be if
1. Evidence of significant pulmonary comorbidity based on abnormal pulmonary function tests (FEV1 below 60%) or aberrant lung parenchyma more than mild on radiological imaging.
2. Perfusion defects and ventilation mismatch on a recent V/Q scan.
3. Arterial perfusion defects on a recent thoracic CT angiography.
4. The following comorbidities associated with group 1 PH:
1. Connective tissue disease
2. HIV infection
3. Portal hypertension
4. Congenital heart disease
5. The following comorbidities associated with group 5 PH:
1. Hematological disorders such as chronic hemolytic anemia or myeloproliferative disorders.
2. Systemic and metabolic disorders such as pulmonary Langerhans cell histiocytosis, Gaucher disease, glycogen storage diseases, neurofibromatosis or sarcoidosis.
3. Chronic renal failure (eGFR below 30 ml/min) with or without hemodialysis